A comparison of the growth, establishment, and maturity of direct-seeded and transplanted sh(2) sweet corn

Sweet corn (Zea mays L.) cultivars containing the shrunken-2 (sh(2)) gene h ave superior kernel quality but often germinate poorly and display poor see dling vigor. The transplanting of sh(2)sweet corn was investigated as a met hod to improve stand establishment and hasten maturity. Three-week-old plan ts (sh(2)cv. Krispy King) were raised in 200-cell polystyrene trays in eith er plug-trays (PT), float beds (FB), or ebb-and-flood (EF) production syste ms and compared with direct-seeded (DS) controls for transplant quality, su ccessful establishment, and early harvest. In 1994, when plants were establ ished in early June, PT plants matured I week earlier than DS and FB plants , which had similar mean times to harvest. In 1995, when field planting occ urred in July, all plants flowered prematurely when only 60 em tall. In 199 6, the experiment was begun in early May, and survival of all transplants w as >85% vs. 54% for DS plants. In 1996, transplants matured 10 to 13 days e arlier than DS plants, however, >90% of DS plants produced marketable ears vs. 63%, 49%, and 44% of EF, FB, and PT plants, respectively. The DS plants were also taller with better root development than transplants in all year s. Transplants produced smaller, lower-quality ears than did DS plants, thu s nullifying the benefits of greater plant populations and earlier maturity . The EF system produced high-quality seedlings because of the greater cont rol of water availability during seedling development. In some areas, the i ncreased value of early sh, sweet corn may be worth the additional cost of transplanting and greater percentage of unmarketable ears.